The invention relates to a processing system for processing substantially identical or at least partly similar items that are to be processed in large numbers and in an ordered sequence either individually or in defined groups and usually in a more or less precisely defined position and spatial orientation. In this kind of process each item or each group of items is processed in a plurality of successive processing steps and is usually conveyed from one processing device to the next via a conveying line.
A conveying device applicable in such processing systems is disclosed, for example, in the publication WO-98/03420.
Piece goods such as bottles or other containers are processed in the following steps: cleaning, drying, testing, filling, sealing and labeling. Printed products are processed in the following steps: completing, trimming, binding or stitching, sorting, addressing, grouping, and packing. The items (e.g. containers or printed products) are mostly processed in a serial sequence of successive process steps while being held in a specific processing position and orientation defined by the processing device. The items are conveyed to and from processing devices, whereby a defined conveying position may also be necessary (e.g. conveyance of filled, but not yet closed containers).
According to the state of the art, such piece good processing is carried out according to substantially two methods, mixed forms with areas of the one as well as the other method are being also used.
One of the named methods is the xe2x80x9cdevice orientated methodxe2x80x9d in which the individual processing devices and the intermediate individual conveying devices are largely independent of each other. For each processing device and for each conveying line, the items are picked up by corresponding holding means and after processing or conveyance are unloaded again. Buffers are provided to compensate for differing capacities and output fluctuations of individual processing devices. The buffers, for example, may be conveying lines without a strictly defined conveying order that allow retaining (e.g. conveying belts on which standing bottles can be retained). The buffers may also be provided as waiting positions in which the items wait for further processing in a more or less unordered manner.
An important advantage to such device orientated processing methods is the functional modularity which allows modularity regarding devices possible and which renders bifurcations and junctions in the conveying line simple and substantially free of problems. An important disadvantage of the methods is the necessary and possibly very frequent handing-over of items from a conveying or holding means to a further holding or conveying means. Such handing-over causes high strain, especially on sensitive items. This is also the case for buffer storages and waiting positions in which the items are retained and are moved in a more or less unordered manner, whereby they are often subject to friction against each other or against conveying means and thus are unnecessarily strained.
The other named method is the xe2x80x9csystem-orientated methodxe2x80x9d in which processing devices and conveying devices are combined in a fixed manner forming a system. In such a system the conveying steps and:processing steps are functionally coupled and the conveying devices and processing devices are mechanically coupled, by common centrally controlled conveying means on all conveying lines of the system. The conveying means are, at the same time, at the holding means for processing in at least part of the processing devices. These conveying/holding means are arranged on a central hauling means (e.g. endless traction chain) by which the conveying/holding means are transported in a forced manner along a plurality of conveying lines and through a plurality of processing steps.
In a processing system that works according to the system-orientated method, all components are subordinated to restricting system conditions. For all participating processing devices the processing cycle is identical and fixedly predetermined or it is variable for all devices at the same time. The processing orientation for the items in different processing devices can differ from each other only within very restricted limits. The main advantage of the system-orientated method is the fact that the items don""t need to be handed over and, therefore, a lot of expenditure for devices is saved. The main disadvantages are the strict conditions regarding the processing cycle and the processing orientation restricting the processing devices such that, in many cases, they cannot work optimally and cannot be chosen freely. A further disadvantage-of the system-orientated method is the fact that conveying bifurcations within the system can only be realized by removing items from the conveying means, creating voids in the conveying stream and reducing throughput further downstream. If the system-orientated method is to be combined with continuous conveyance, conveying and processing must be synchronized very precisely which involves a large effort, particularly for larger systems.
In order to reduce the named disadvantages of the device- and system-orientated methods it is common, as stated above, to use mixed systems with regions of the one method and adjacent regions of the other method. Thereby, the choice of method in each region is, in particular, defined by the kind of processing device to be used.
It is an object of the invention to create a system for piece good processing that is in its nature system-orientated but allows integration of processing devices posing the most various conditions. Thus the inventive processing system is to unite the advantages of the above described device-orientated and system-orientated method for piece good processing while at the same time avoiding at least a part of their disadvantages. The inventive processing system allows full automation but, at the same time, allows manual process steps also. Furthermore, the inventive processing system is easily adaptable to the most various items to be processed, in particular to items of which not all are to be processed in the same processing steps, i.e. are not to run through the system on the same conveying paths. The inventive processing system is also adaptable to the most various spatial conditions and is easily extendable.
Items to be processed are supplied into the inventive processing system and processed items are conveyed away from the system. Furthermore, auxiliary materials may be supplied to individual processing devices of the system and/or conveyed away from such devices. The system is functionally closed in itself and consists of a plurality of functional units that are at least partly represented by mechanical units. The mechanical components of the processing system according to the present invention include:
a conveying system comprising a rail system and a plurality of conveying/holding means that are independent of each other and serve for the held conveyance of items or groups of items and are displaceable along the rails of the rail system;
least one loading device and at least one unloading device serving for loading conveying/holding means with items or groups of items and for unloading items or groups of items from conveying /holding means;
at least one processing device serving for processing (in the broadest sense of the word) items or groups of items.
The rail system is substantially closed in itself and the independent conveying/holding means are displaceable on the rails in a predetermined direction by a plurality of corresponding drives. The rail system may comprise bifurcations and junctions (switch-points). Rail system and conveying/holding means are matched to each other such that the orientation of the items relative to the rails are within wide limits freely selectable and locally variable. This means that the conveying system of the inventive processing system defines conveying lines which can comprise, freely selectable within the broadest limits, rising and falling regions as well as curves and on which different relative orientations are made possible wound rail sections and/or by variable connections between conveying and holding means.
The rail system connects loading devices with processing devices, processing devices with subsequent processing devices, processing devices with unloading devices and unloading devices with loading devices, whereby the rails extend through the devices or bypass them. The conveying/holding means are conveyed along the conveying lines between loading, unloading or processing devices and through devices, either driven by drives or passively, i.e. without mechanical drive, e.g. with the aid of gravity on falling conveying lines or with the aid of previously collected kinetic energy on so called run-out lines.
The conveying/holding means form compressible conveying streams as long as they are distanced from each other along the rails and they are individually driven in such compressible conveying streams. Conveying streams in which the conveying/holding means follow each other along the rails without being distanced from each other are not compressible and can be conveyed by driving only the rearmost conveying/holding means in a pushing manner.
Upstream of loading, unloading and processing devices, entry control means are provided. The entry control means serve for bringing supplied conveying/holding means or items or groups of items held by conveying/holding means, respectively, into a spatial orientation and for establishing a temporal sequence of items whereby the orientation and temporal sequence correspond to the conditions of the loading, unloading and processing devices. Upstream of the entry control means, the supplying conveying lines are designed as collecting sections, i.e. as a line section along which conveying/holding means (empty or loaded), in which items that cannot be processed immediately are retained in an orderly manner.
The conveying drives are advantageously arranged along the rails and interact with the conveying/holding means by an effective connection. Between driven conveying line sections (those having active conveyance), there may be sections with passive conveyance. The conveyance through loading, unloading or processing devices is matched to the function of the device. Drives serving for conveyance only advantageously have a substantially constant or unchanged speed whereby fluctuations in the throughput lead to fluctuations in the distances between the conveying/holding means. In other words, it is more advantageous to compress the conveying streams than to increase the conveying speed for increasing the throughput. The collecting sections are advantageously designed as lines with passive conveyance.
The system comprises, as functional units, a plurality of stations that are largely independent (autonomous) regarding control, i.e. in particular independent of each other. These stations are processing, loading and unloading stations each comprising a processing, loading or unloading device with an entry control means allocated to the device and a conveying drive which possibly drives the entry control means also or even representing it. Autonomous stations may also comprise a plurality of identical or different devices arranged in parallel or in series and comprising corresponding entry control means and conveying drives. In addition to the named devices, autonomous stations can also comprise rail bifurcations and/or rail junctions. Alternatively, rail bifurcations or rail junctions may represent autonomous stations themselves, with or without entry control. Finally, the system may comprise autonomous stations serving for conveyance only and comprising a rail track and at least one suitable drive.
The autonomous stations of the inventive processing system comprise control means with station-internal actors which, in constant or clocked manner or due to momentary conditions (sensed by sensor means) in the station or in the immediate surroundings of the station, act directly or indirectly on the conveying/holding means (e.g. conveying, accelerating, decelerating, establishing predetermined orientation) and/or on items (e.g. establishing orientation, processing). The control means of the autonomous stations control, in particular, the entry control means, conveyance through the station, temporal sequence of functions of station devices (cycle regime) and possibly processing modes to be carried by station devices (processing regime).
For controlling and mutual matching the throughput of the autonomous stations or the station devices, respectively, it is advantageous to provide central management means. The function of such central management comprises, in particular, the adaptation of the throughput of the individual stations to conditions from outside of the system or to system-inherent conditions (in particular to the filling state of collecting sections) and possibly the optimization of system operation by coordinating the throughput of the stations. The central management may, furthermore, take over configuration tasks and central security functions. The central management may comprise own sensors and/or actors or use those of the autonomous stations. The central management is advantageously automated but can, however, be operated manually.
Due to the high flexibility of the conveying system, the high autonomy of the system stations (which substantially means a high autonomy of individual devices or device groups), and the clear division of tasks between station-internal and central management, the inventive system has a very high integration ability for devices with the most various demands and a modularity that is easily adaptable to external conditions and easily extendable. All the same, each item is conveyed through the system by substantially the same conveying/holding means and handing-over steps are not needed. This protects the items and simplifies processing and conveying. These advantageous characteristics are supported by corresponding characteristics of the system components, in particular of the conveying system.